From: Cyrille Pitchen Subject: [PATCH 2/2] crypto: atmel-sha - fix race in atmel_sha_final() Date: Mon, 8 Feb 2016 16:26:49 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Cc: , , , Cyrille Pitchen To: , , Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org When (!ctx->bufcnt && !(ctx->flags & SHA_FLAGS_PAD)), the former source code used to set the SHA_FLAGS_BUSY without checking whether this flag was already set. If so, the hardware is already processing another hash request so the processing of the req argument of atmel_sha_final() should be delayed by queueing this request, the same way as done for the (ctx->bufcnt != 0) case. Signed-off-by: Cyrille Pitchen --- drivers/crypto/atmel-sha.c | 24 ++---------------------- 1 file changed, 2 insertions(+), 22 deletions(-) diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c index 7d27f96cdf02..596e489a4ca9 100644 --- a/drivers/crypto/atmel-sha.c +++ b/drivers/crypto/atmel-sha.c @@ -979,37 +979,17 @@ static int atmel_sha_update(struct ahash_request *req) static int atmel_sha_final(struct ahash_request *req) { struct atmel_sha_reqctx *ctx = ahash_request_ctx(req); - struct atmel_sha_ctx *tctx = crypto_tfm_ctx(req->base.tfm); - struct atmel_sha_dev *dd = tctx->dd; - - int err = 0; ctx->flags |= SHA_FLAGS_FINUP; if (ctx->flags & SHA_FLAGS_ERROR) return 0; /* uncompleted hash is not needed */ - if (ctx->bufcnt) { - return atmel_sha_enqueue(req, SHA_OP_FINAL); - } else if (!(ctx->flags & SHA_FLAGS_PAD)) { /* add padding */ - err = atmel_sha_hw_init(dd); - if (err) - goto err1; - - dd->req = req; - dd->flags |= SHA_FLAGS_BUSY; - err = atmel_sha_final_req(dd); - } else { + if (ctx->flags & SHA_FLAGS_PAD) /* copy ready hash (+ finalize hmac) */ return atmel_sha_finish(req); - } - -err1: - if (err != -EINPROGRESS) - /* done_task will not finish it, so do it here */ - atmel_sha_finish_req(req, err); - return err; + return atmel_sha_enqueue(req, SHA_OP_FINAL); } static int atmel_sha_finup(struct ahash_request *req) -- 1.8.2.2